Sensory Issues with Autistic Spectrum Disorders

Autism and Asperger’s Syndrome: Sound and Touch Sensitivity, Taste and Smell Aversion, Balance and Coordination Problems, and Sensory Integration Therapy

Sensory Overload
Image Courtesy of Salvatore Vuono, FreeDigitalPhotos.net

According to Dunn et al. (2002), unusual sensory processing is a hallmark of autistic spectrum disorders (ASDs) such as autism and Asperger’s syndrome, and many experts believed that other symptoms of ASDs arise as a result of these sensory abnormalities. For example, obsessive preoccupations with special interests or parts of objects, the compulsive need for routine and ritual, and the tendency to engage in repetitive motor activities (i.e., rocking, hand flapping, etc.) when under stress may all arise from a unique way of perceiving the world. In particular, repetitive motor activities may serve to block out overwhelming stimuli (Wen-Shing & Mei-Hwei, 2009).

Senses ruled by the nervous system include vision, hearing, touch, smell, taste, motion, and sense of body position. The body’s sensory systems send information to the brain, and the brain figures out what this information means and decides what to do with it. Children with ASDs usually have normally functioning sensory systems; it’s the processing by the brain that is atypical (Dunn et al., 2002).

According to Jones et al. (2003), examples of sensory abnormalities include:

    • Distorted perceptions of physical objects, depth, or body positioning
    • Periodically tuning out certain senses (failing to notice certain sounds, sights, etc.)
    • Synaesthesia (sensory cross-wiring – i.e., perceiving colours in relation to smells, textures in relation to colours, etc.)
    • Difficulty processing information from multiple senses at the same time
    • Sensory overload

Those with ASDs tend to be either over-responsive or under-responsive to stimuli such as sounds, tastes, texture, smells, sights, and other body information.

Traits That Characterize Over-Responsiveness and Under-Responsiveness to Stimuli (Adapted from Dunn et al., 2002)

Over-responsive:

    • Easily distracted
    • May be hyperactive
    • Derives great joy from activities that aren’t enjoyable to most non-autistic (neurotypical) people, such as making certain sounds, repeatedly touching objects, watching ripples on water or a crawling bug for a long time
    • Highly irritated by things that don’t bother most neurotypicals (i.e., a ticking clock, “normal” touch, textures of common foods, certain types of lighting)
    • Extremely distressed by things that others just find aggravating, such as sirens or car horns
    • May appear to have “super senses,” perceiving things such as an approaching airplane before neurotypicals do
    • Has difficulty filtering out competing stimuli (i.e., working when people are talking nearby, or focusing on a conversation when the other person is wearing a tie with an interesting pattern)
    • May adhere to rigid rules and rituals to control the immediate environment in order to limit confusing, stressful, or overwhelming sensory input
    • May avoid situations or places that are over-stimulating, such as crowded shopping malls
    • Avoids certain foods, fabrics, or other things that are perceived as unbearable (i.e., will only take baths rather than showers)

Under-responsive:

    • Fails to notice what is happening nearby
    • Appears to ignore sensory cues (i.e., someone calling his or her name)
    • Uninterested in surroundings or people
    • Clumsy (low proprioception)
    • High pain tolerance/ physically tough or stoic

Dunn et al. (2002) note that people with ASDs may fit one profile for auditory stimuli and another for taste or touch. For example, a person on the autistic spectrum may be traumatized by many types of sound and avoid loud or high-pitched noises but be oblivious to things that bother others (such as certain types of pain or physical pressure) and compulsively drawn to certain textures.

Sensory anomalies likely contribute to the preference among many of those with ASD for communicating online rather than face to face; on the Internet, they are not be overwhelmed by eye contact and the necessity to manage their own body language, attend to the body language of others, and process sound and visual input simultaneously.

Prevalence of Sensory Issues in Those with Asperger’s Syndrome

Sensory anomalies are not confined to more severe autistic spectrum disorders. A study conducted by Wendt et al. (2005) found sensory anomalies in 91.4% of those with Asperger’s syndrome (a relatively mild autistic spectrum disorder). The prevalence of specific sensory issues was as follows:

    • Touch: 53.4%
    • Sounds: 50.0%
    • Smells: 44.8%
    • Light: 43.1%
    • Pain: 15.5%

It is also worth noting that 60.3% of those in the study had aberrant eating habits, which in many cases may be caused by unusual sensitivity to the taste, smell, or texture of certain foods. Many people with autistic spectrum disorders eat only a small selection of foods because they find so many textures or tastes abhorrent. Choosing relatively bland foods such as bread, rice, pasta, French fries, or peanut butter is common (BBB Online Autism Support Network, n.d.).

Note: Asperger’s syndrome has been removed from the DSM as a diagnostic category, and is now considered part of the larger autistic spectrum. However, many people still use and identify with the term, and it has been an area of focus for prior studies, so we continue to use Asperger’s syndrome in this article series. 

Sensory Integration Therapy for Autistic Spectrum Disorders

Sensory integration therapy is based on the assumption that sensory processing deficits underpin other problems associated with autistic spectrum disorders, ranging from anxiety in new situations to social withdrawal to the compulsion to engage in repetitive motions. Provided by occupational therapists, the treatment is expensive and requires a time commitment of 2-5 sessions per week (Hyatt et al., 2009).

According to the BBB Autism Online Support Network (n.d.), the goals of sensory integration therapy are to improve not only sensory processing, but also responses to stimuli. Many activities are particularly focused on:

    • Integrating tactile sensory processing (over- or under-reaction to touch)
    • Improving proprioception (positioning of various body parts and by extension, coordination and grace of movement)
    • Enhancing vestibular function (stability and balance)

Depending on the particular sensory issues to be addressed, techniques may include:

    • Wearing weighted vests
    • Handling items of various textures
    • Brushing (the therapist runs a soft surgical brush over the client’s skin)
    • Deep pressure massage
    • Walking on balance beams
    • Balancing on large therapy balls
    • Use of compression devices

Additional activities that may be helpful, which clients can undertake on their own, include:

    • Tai Chi
    • Water aerobics
    • Rocking in a rocking chair
    • Strength training/carrying heavy objects/moving furniture
    • Upside-down activities such as tumbling or headstands
    • Having firm pressure applied to the skin via hugs, compression devices, or massage

There is currently no empirical evidence supporting the use of sensory integration therapy, though it is difficult to study such interventions effectively due to the varying methods used (Hyatt et al., 2009). However, parents swear by these therapies: a recent study indicates that 91% of those who sought sensory integration therapy for their children have found it helpful in reducing autistic mannerisms such as making noises or engaging in repetitive hand motions, as well as improving social functioning, emotional regulation, and motor coordination (Temple University, 27 April 2008).

In Some Cases, Sensory Anomalies Can Be an Asset Rather Than a Liability

The sensory problems associated with ASDs can make it difficult to participate in certain activities and often create stress for thsoe with ASDs and their loved ones. However, they can also be beneficial in some cases. For example, sensory anomalies can support the cultivation of various talents:

    • An individual with unusually strong auditory perception and discrimination may have the capacity to become an excellent musician.
    • Under-responsiveness to physical stimuli may enable a person on the autistic spectrum to engage in certain rigorous fitness routines or athletic pursuits that neurotypicals would find difficult to maintain.
    • A strong visual sense could predispose an individual to talents in the areas of fine art, photography, or architectural design.
    • A profound sense of taste and smell could underpin impressive culinary skills.

It’s also worth noting that unusual sensory experiences are not always traumatic. Firsthand accounts of people with high-functioning ASDs collected by Jones et al. (2003) indicate that sensory abnormalities often enable them to derive fun or even euphoric joy from simple, free activities that would not be pleasurable for most neurotypicals. In addition, unusual sensory processing can lead to fresh perspectives and in some cases, strokes of genius.

For more articles on autistic spectrum disorders, visit the main Autism page.

References:

    • BBB Autism Online Support Network. (n.d.). “Sensory Integration (SI).” BBBAutism.com.
    • Dunn, W.; Saiter, J.; & Rinner, L. (2002). “Asperger Syndrome and Sensory Processing: A Conceptual Model and Guidance for Intervention Planning.” Focus on Autism & Other Developmental Disabilities, 17(3), 172-185.
    • Hyatt, K.J.; Stephenson, J.; & Carter, M. (2009). “A Review of Three Controversial Educational Practices: Perceptual Motor Programs, Sensory Integration, and Tinted Lenses.” Education & Treatment of Children, 32(2), 313-342.
    • Jones, R.P.; Quigney, C.; & Huws, J.C. (2003). “First-hand Accounts of Sensory Perceptual Experiences in Autism: A Qualitative Analysis.” Journal of Intellectual & Developmental Disability, 28(2), 112-121.
    • Temple University (27 April 2008). “Autistic Mannerisms Reduced By Sensory Treatment.” ScienceDaily.com.
    • Wen-Shing, H., & Mei-Hwei, H. (2009). “Ritual Behaviours of Children with Autism Spectrum Disorders in Taiwan.” Journal of Intellectual & Developmental Disability, 34(4), 290-295.
    • Wendt, T.; Paavonen, J.E.; Ylisaukko-Oja, T.; Sarenius, S.; Källman, T.; Järvelä, I.; & von Wendt, L. (2005). “Subjective Face Recognition Difficulties, Aberrant Sensibility, Sleeping Disturbances and Aberrant Eating Habits In Families With Asperger Syndrome.” BMC Psychiatry, 5:20.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.